Professional military and law enforcement need more versatility in the operation of charging AR style weaponry. Prior art charging handles are known to provide a latch which locks the charging handle in its fully forward position. There have been many upgrades to this design, but most designs have centered about a latch which must be manually released by an operator prior to movement of the charging handle and are not capable of disengagement solely by rearward force alone.
Operation of an AR rifle relies on gas pressure siphoned from its barrel during live fire. This gas pressure is released into the upper receiver in a reduced state during the cycle of the weapon. Further, this gas pressure exerts some force against the combined surface on the charging handle with a net rearward impulse resulting. It is this rearward impulse that the latch must counter.
During operation, forces within the upper receiver act to apply a force against the charging handle in the rearward direction. A charging handle must not move during the operation of the AR rifle (or weapon) in live fire.
A prior art conventional military specification (mil spec) design charging handle 6 is illustrated in FIG. 1. Charging handle 6 is positioned fully forward in an upper receiver 3. A charging handle latch 7 is engaged with a charging handle latch pocket 202 of upper receiver 3. Charging handle 6 is held in place by a pivotable charging handle latch 7 that pivots about a fulcrum pin 8 in relationship to a compression spring 9 and the charging handle latch pocket 202. Compression spring 9 exerts expanding pressure between a bottom of a spring bore and a spring landing of the charging handle. This force causes a clockwise torque around the fulcrum pin 8. In turn, this clockwise torque causes an equal and opposite force at the latch surface 200 directed downward into charging handle latch pocket 202 thereby retaining the charging handle 6 in its forward position.
Particular to a mil spec design, latch surface 200 of the mil spec latch 7 is flat and parallel to a latch pocket surface 201 of charging handle latch pocket 202 as illustrated in FIGS. 1 and 2. To release the mil spec handle 6 for rearward movement, an operator must apply rearward force on a handle surface 203 of mil spec latch 7. This force must cause counterclockwise torque around fulcrum pin 8 sufficient to overcome the retaining clockwise torque exerted by the compression spring 9, thus allowing counterclockwise rotation of the mil spec latch 7 about the fulcrum pin 8. As the mil spec latch 7 rotates, latch surface 200 separates from latch pocket surface 201, and the charging handle moves rearward. However, an operator cannot apply pressure to an opposite side 204 of the mil spec charging handle 6 to move the handle rearward. The mil spec latch 7 would retain forward location by virtue of the engaged latch surfaces 200, 201.
More recently, a charging handle has come onto the market that has a fully rounded latch. In that product, the engaged portion on the latch is fully rounded and drops into its corresponding latch pocket. However, a rounded edge may apply inconsistent force to resist rearward gas impulse.